Abstract: According to an embodiment of the disclosure, an apparatus for a flow of fluid includes a first and a second element that form an exponentially changing restriction between them for a flow of a fluid. At least one of the first and second elements is configured to move in response to changing pressures to change the restriction. One of the first and second elements includes a wall with one or more cutouts that have an admittance that changes exponentially with respect to the movement of the first or second element.

Abstract: According to an embodiment of the disclosure, an apparatus for a flow of fluid includes a first and a second element that form an exponentially changing restriction between them for a flow of a fluid. At least one of the first and second elements is configured to move in response to changing pressures to change the restriction. One of the first and second elements includes a wall with one or more cutouts that have an admittance that changes exponentially with respect to the movement of the first or second element.

Abstract: According to an embodiment of the disclosure, a retrofit for a system using a fluid to transfer thermal energy in a system that utilizes a thermostat to regulate a temperature associated with a terminal is provided. The retrofit includes a return line temperature sensor configured to measure a temperature of a fluid leaving a terminal; and a circuit. The circuit is configured to: receive a signal from a thermostat, the signal commanding a modulated valve to open or close; receive a temperature from the return line temperature sensor; determine whether the temperature is either greater than a maximum set point or less than a minimum set point; and modify the signal from the thermostat if the temperature is either greater than the set point or less than set point.

Abstract: According to an embodiment of the disclosure, a retrofit for a system using a fluid to transfer thermal energy in a system that utilizes a thermostat to regulate a temperature associated with a terminal is provided. The retrofit includes a return line temperature sensor configured to measure a temperature of a fluid leaving a terminal; and a circuit. The circuit is configured to: receive a signal from a thermostat, the signal commanding a modulated valve to open or close; receive a temperature from the return line temperature sensor; determine whether the temperature is either greater than a maximum set point or less than a minimum set point; and modify the signal from the thermostat if the temperature is either greater than the set point or less than set point.

Abstract: According to an embodiment of the disclosure, a system for regulating a pressure differential includes a plurality of valving elements and a valve activation system. Each of the plurality of valving elements are configured to selectively allow and restrict at least a portion of a flow of fluid between an inlet and an outlet of a conduit through a respective opening and closing of each respective valving element. The valve activation system is configured to supply a common driving pressure to the plurality of valving elements. The common driving pressure is configured to initiate at least one of the opening or closing of the plurality of valving elements or to initiate the other of the opening or closing of the plurality of valving elements.

Abstract: According to an embodiment of the disclosure, a retrofit for a system using a fluid to transfer thermal energy in a system that utilizes a thermostat to regulate a temperature associated with a terminal is provided. The retrofit includes a return line temperature sensor configured to measure a temperature of a fluid leaving a terminal; and a circuit. The circuit is configured to: receive a signal from a thermostat, the signal commanding a modulated valve to open or close; receive a temperature from the return line temperature sensor; determine whether the temperature is either greater than a maximum set point or less than a minimum set point; and modify the signal from the thermostat if the temperature is either greater than the set point or less than set point.